SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1087cbbf48f97973da230ae162525c0cd6069157e5ed17899f1b9e22a404f3e9' 
  AND token = 'V5T6pMmpEUesXcQbBJRt/tX4wuxnRhf4gAHJyikARbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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