SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96ef4ccb083f9008535363c2a2c73bf4a9949803ba4b094171c374749bfeb551' 
  AND token = '+8z7UtjiezBERGzKVJffR0Y0fO+wENI6+DcIUOLpucY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}