SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35101768b236377fd588581c5db598aaf134cea2c9a463b530ee89fb1424aa85' 
  AND token = 'DIqVo7DT/jpjL4ajFIFmZJhGmaEV7dkPRdyJmacj7gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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