SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfadbb45ccfd3e3af48686c56b44e6e39c2a4a385766ddfa291f18501d791dd4' 
  AND token = 'i1hFp7Lq+jQ9RHDhCL3qmNUzM4ja7S5oSg0mw9Ztzmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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