SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e552e307446af09556c3a197dbeb5dc80bdbf21248f27a2cd9304313d2f79ef7' 
  AND token = 'nUzqwJ56eXZX/EsIRMH7MwJYTGQHgzD/+1wiSTJ4Yok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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