Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '268d764eb9d9c9f78c4f4113c71ff58a6d6ed6b7d8907e90bb15fb0e6eac20b0' 
  AND token = '9Kb7dqdD1jNaA+DQ3yR0KjlnfqGJKGHli+MXHuJj00I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}