SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85b7723a2f0963aaf7c092e523b29d3b2b42fb6a634ded785f27186c8a7820fc' 
  AND token = 'rrOtRHlhEz9+V8PIKiJW5/1BDu3hSlvasD0XRzQ25PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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