SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94976d391aa127409960afdc8990f6d88988c5c8fcb15858ba3d7247fcbd07cd' 
  AND token = 'bmVJEky9hVRAwDA0t0K/tZIjWTtohyV533lJHBjpQ7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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