SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc31ae0e8c74e8d8bbdbd23fa479a6a17810083294010fc6be9a30684969932a' 
  AND token = '1wkRuC6QMFCQ16V3pewBZuT08PkhYt9D9gC3FSI7nF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}