SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5c76b6e0088d953536d750187b1ec1a3411fcbf22bb03a947f2580b0cfdb448' 
  AND token = 'TLjIjBCmVHac94mOUJ6pmWX5tV7he+Y0UKZrzOChGbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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