SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50d79149e1edad60637fcab9b9e3b2a4b91ab12b478844a14b2fb7820ca3c04c' 
  AND token = 'tGHgtUAwYPiGPYufJo4XQR87qg8huEWJz/yNlrRpm6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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