SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6b61bb840f21547a113a399e6bdb9663b77efb971bc8e5b12c29da22b6dfb29' 
  AND token = 'hPjNAjbDWRD5UmSoebN1COEYnQ4eGDeFWxx0+7iXM4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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