SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9d505acfbbaeadfb154fcc286bec322f6c0f898522c70e15c0f238d712cdf27' 
  AND token = 'E3MXy3MP7+y8bdfVSAPiUSC5tQ65rWXzCqNphL2kysM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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