SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfc2166c17ba2a345b882dd534afbaf35093a559d6dec40ebd49d17492311657' 
  AND token = '+IvRlIFTnT2pXYM3V7hlUWu1VJzVtNw5PmpTLS5Z2YU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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