SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4403178fc4c5c0fde887ef0b5d7ff7e347ed4fde7202487298208e1ea0d44bea' 
  AND token = 'k1BiBuvTFnTz+lFSslJwNRVX90rhkgqvAknj/ZfrNDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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