SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '31dd7187c4cc5b057ff4d65bd8b2fc93d22777b13a23c2e3004eb196d19e0647' 
  AND token = 'HlCAPgTTaAWU6T9hzE00WnIrDHoHtaDKOhz2zr1O2mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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