SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '358f80d1a89bb6b977758f7a8b1d73e6bcf0cf2da691d1107c32d4c723eee628' 
  AND token = 'N/cL8GpDEDOeJ64J1hj3W6AhftrVrmfOEWCXRkNqKTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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