SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '412efbb3ad23bef8118b9226c274c68bc5830d2cc11f75a818361cdf7b6e16f8' 
  AND token = '4fICkiHua8w+mKouVZAxn3RcSJwV4n0ZOMw0NoEQIko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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