SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdb7841a1b7cd87711f1851c46ee2398244b9ace0e9707a08da064112e1d6fa4' 
  AND token = 'Gws8nK+ODPLLTssxWfWM1ijxMnfKd9ZjNJZlv/EShkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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