SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06113cf73903671a536b5198446113ec9b9785ad6a44e20fde782938050cdf51' 
  AND token = 'Y4MQIhlUOqnMgHRb+ny51M1RTnH5v7VAsdjHYkIJvCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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