SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2385b11f4915a31b3c986797cba74ea7c4fee56a6a69472fa9456670a836e0d3' 
  AND token = 'u/0k7tMNrwIqZt/pWFa1R2tLkEzXnx/TWAeUP28Uxpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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