SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '449b048f0bd7fbf5ce9ed393f1c0bff1ed87263010e3ea17236e746403b15643' 
  AND token = 'eR9WwJjX9eOJZTP23vmwYLfBt1u7hw5u6byXMtCOuC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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