SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c7d2bafd1eb6f0967f956f01d6bc830262446c5e05c2c2e0216f73d9adfce5ca' 
  AND token = '/GdnbcE1i3AMuRCkhjSTF3ei1VN4vTVL4jdV5U3j2NI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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