SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0662e5a4239c014ffbb144fec426d592400ccdf25b9069582b1395fced033b1c' 
  AND token = 'QYYan7jwrTgYKCsADupheYRcBof1i3j9vI7PoGmmAsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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