SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8041103f36a96c33b88541a34311e8dc71cb410ad720faf15f64c25ed2095d08' 
  AND token = 'XOzjaWJT16d+1e4lCfg9TdqMbh4ihGXlrtEbDNEL/tg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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