SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48a7282a9989dafed6fc956e79333a06918984f095aad0a3ebd4235625758f08' 
  AND token = 'BsbfNbNH8rNtNzKxg9pG9kB7qHVR9nN68q2hlqRlMUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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