SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c2ce3e8184d06dde5d2d751d655bffd8245a9ad8530f4778d974223a3b08cd9' 
  AND token = 'Ryxzi3NQS816A+F0bOmxdnl7VE9RcSXAMXhYVE4RZro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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