SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a085d31e87702b89b88da361fcc25908204a9db7f9319651baef3a7ec127fa88' 
  AND token = 'GKq4g5TkrorkrnDA3KawuDCk9mB+YL0xdRg3OLCOIAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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