SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3fb5b2362041db983586ab65b8bce8919519aaa4429f0f91fdb41f81d0079a7' 
  AND token = 'fDdUPeOGeowZABqqMCDcQNJmStbhU2dA5AR5E9a4rhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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