SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '49c158a2765030ab6733d88a736fa7e5b7d7cb06c990ef3cf24695b8b507b8aa' 
  AND token = 'ZETuaTaTgGczqqB2UvJdP5PFnauDltjvRD6oMQIWkx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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