SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b83a20ae3a5782b0d694fc1c58517cf8e73b6ce09bab57df029542e919199c6a' 
  AND token = 'oYNBhW3iQLayqDQUx5rIjElXZHF+UYgyUA/EPBqDUfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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