SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '915f07e2755e27b65ada6c8b99fc33454629c42176187d00d289a543ee5ddbb8' 
  AND token = 'v8zw+YJZTHfudzzL99Oe4P6+MUo83dj2vuNu6qnatG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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