SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a8004c953b3ed759c012b29b9d3473ce8f3ad9199eb65ba1d526b2e537a736b' 
  AND token = 'fNzM5jmNmSp6evKfoazlwxEOicCHjobh4lKrT2cXJw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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