SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2869dad4662d1f4e081a32a1010a881be697eea3364424b8177472363c837ffd' 
  AND token = 'lOTPZ4KRUkFGpBmWKD/DiJ/GVbBbfK4tcjNhgOW5/4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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