SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '39d0ff00c9715833f60687d362a01c7f50d12d04ea8c0d216a11404f9470ed5f' 
  AND token = 'cyRv9lXpXrc95RCSgpQ27Gg4vJlEOy+5jkmR79LqKYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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