SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fcf99da0e918e64da433dd37d8d169f03d70d5a659d6b9dd5be45ccb9c54f37f' 
  AND token = 'iRGfQQLhyxTdcspkKDSkcr4tM4gwAx6/EdnD2j4EvGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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