SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6386562b7dc3c0dc1f31e8148423b64d55a145638ebbce6cfff9835300c9e07' 
  AND token = 'jTefhYoDqcKP1DBjuNyTedMUc3HRUsbxLUxfsMrO+dk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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