SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7038ff9bbbc9f681f3637b4804527866e1df1bdb671ff873f6a58ebc511970ab' 
  AND token = 'cvM3h1QeSbPUcU8Wzx+Gar30/TaJNWJ72lTMu2q9B4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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