SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89602beca4bf959b23bd7e4f5b41ef381bd13a930a8fca6b4d703409d262c778' 
  AND token = 'uq03ZIR5YUUB+c+GiXdvpy8/1SDckgIOVp6l3VR9DOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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