SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abbf17b08821c1e6c189596aa1b2fc0a0dca22edb2c08a919f06785a6591b967' 
  AND token = 'noV3HjsKaV3fONBKg2Q4UjNxDmZRsGuOfz/UFixz5Y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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