SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35ba13b1ee3997f30953f9acaf061b6727364d41f161c1cfdaa57d8b7349c943' 
  AND token = 'lEPrILXnnxpMCeHHaUKvQWv039HFxUsrKo5veMqcoU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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