SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf0a99e3f60c6de9eefe8c0cc7273996775e9eb71c57e65f2632c2a7ce65336' 
  AND token = 'JLP9yMBApZKg78WvgYcTeac0ASyJMvx+I17TPH5WApo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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