SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '467642f897a949b32985fbefb28f85c219f3580d8836293cb1ff69ebf8f831cc' 
  AND token = '3giMgRHKlXKWEBwCvCEWzrQZzacxDtYTmWyCgak8VHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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