SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96446a5a321015fe62f28271cba43f589780232cf7b6069c31acac232aa1cac6' 
  AND token = 'zNr8BgTUwlfcKDn0pXaJztPh4UhRmNxMzDFlsvW08Ls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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