SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7011361f2deed8acd6b5184ed8c0542baf1ea8d291d9ef0567795e976a31c312' 
  AND token = 'zSpAnhRLYiq7qK1WCLUGLwleOYl98QZFMKLyKW3Pv7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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