SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9310d89c9307eaa8cf9f94110e0616d724a5d3db040281235f5401aaecd724e1' 
  AND token = 'pomw1zuoGxw5/11oroHBvGdrFYuEaIsUkAZXhIP8bDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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