SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '767d5dd0c674e0c12431a46328e5cfbccae9c65826cda12f23227b07f01bb4f1' 
  AND token = 'Asd6V85J4KklhVnqx+33VobiAVhaiugSbk8JM5HTz/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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