SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a26c56f875b8ecb6f6c7d70bd379a9b66616735fb1f7234e84f222fa8b797285' 
  AND token = 'rhlPzQcHqrzG9LdMYynIFsoIO4dF9pWhhnvlbCBzOOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}