SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc948929e379996115c774c14a335006876258cf06910c0e772828188b2517fe' 
  AND token = 'i0ymvNTf/+cRgrNUoWud3XPxwxbShOwF4/KJ3qkmma8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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