SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93339f993f40a756f6f21ab3ce630ce39f9143ab5a4562269db94907c1798be8' 
  AND token = 'VR78QyP4qhRWrYgBbLiQDdmwa1fMLiXDswS/TJQCG58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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