SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2bf10427d30ba9cf167e47f6eba92ee612880d609b7996013dcd60ee9c88c549' 
  AND token = 'oW2vAKjl8JquIwk4haCG0guIDwjjcrEIExHhCog/OC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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