SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f19a49663e0cbed8da399e7d2963e278936276c2101b64d83933c101fccae8ec' 
  AND token = 'vCpEkAtQ9TQQT4LlR1gVNrXA+3FBieGChAK6LiRRevI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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