SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c846bd071eade85e6c3f484805ac839bfa782bfe411212bc0a3a39dae88448d9' 
  AND token = 'N+Mi5ZNsNPhieKxsPxqoulQcjigPiIdTVusRNP94Rck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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