SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '266fc4136f7bb3c254115e09653d9fe475532d08c19340b70cdccb52d21dfac6' 
  AND token = '+Niitf4ctg7MwwZ5bzjXs0EDLP5IMp27aM1tEkDA2v8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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