SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2ceb6b979a02a4fe6316dce904a92a3b6daffda9b2d441b6267e0ec3c0fb87e' 
  AND token = 'h4IgrVUfEXRlhYzYMhJK/8dlWlQEm191xIu7VgdzpUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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