SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c45fdda0d225b94e31d599352e19849e0df481d0b453ef4c82c6d51c789f5a1' 
  AND token = '1MyjViPciZnYnVwjdy2RzuplPiarYL5CiMNlvg7Q0Ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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