SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddef6c4405ccbe0a3092def9bd06cf8d4d5a3162117a7b938d48c893a1a77218' 
  AND token = 'JZp6yYbnuzrImpL7z16963ggNnwGgkrK0A9NyDOkoyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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