SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b60ae0b786df7fd2a7130381ad7528fa3b3eaf2eed522c3a50a378e2d87a0f0' 
  AND token = 'ailm/hSRcJ5WCn/70tRIPRkOnBrJ1FTdNyzDtkeR958=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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