SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '825ee5cc2c16f2abd87988f831b49a18b3fd50a4eec44359ca85a2e6fe96ed54' 
  AND token = 'YKTJmg1Jd/xSw12B2UbjDlXh0IRts12G9QSrBK6XvRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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