SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecf3be5846467f6ba8161e8d70467e0cfba903681104852afdde454b94ebc611' 
  AND token = 'oMUEYyCN60b3DjL4XS6kE6IeXuFGxMsFd72QN97vTeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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