SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2771aec086ee529971476ba20c8482cd82acec1d733b22783169b02100b4b852' 
  AND token = '3AkfV1UfU6X/9buroAl57RaoiD0SY8kbmLtidRNwvPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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