SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59c1b35d012f0afc72f5f8b42bb996c87f3f35cda9b37df44c46e5f0253c82d1' 
  AND token = 'M7oKXkoXqKNkHpbzocjLB0zxDRKsmosLrczxzajb3nU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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