SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd69170cfd1900513bfd5a7692327e872c008892816e0194711b65f147576fe88' 
  AND token = 'bFG6DMsZpG4/91XmaIZniVN47SjuOIJT/p2jDfesTa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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