SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea4604720f4c09d0867b304613f04d3811f9689e56c3ea580c29e48fee00cccc' 
  AND token = 'lRb2m/rqXppveB9PpgAeLrrZ7QQMjyiOGJFCGCLGODQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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