SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3188f003204ea2f6e5e07cf383f4b8f2c27f6e5a8e1768cc16d2a83086708bac' 
  AND token = 'yugeJqyK9Q6XOiVzGDK9sph9fIgiLAKqXw2znlLbdOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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