SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f5790ce77935852dc259569bbbe1488872fe0004b33ff352ba8b33a02178331' 
  AND token = 'cagfoFwRhljjhMBgbF4GRm+54+wWyXWVk6nJO2E5f/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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