SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94bfe4367ee4b7253011a101d7b21264efc6f885a7eb7310366d64ed9681f84f' 
  AND token = 'Yz54dMCn6WY16aW87vsdI4ZtHRMWFwrpc1DfTUqUnlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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