SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51585364b6526e1b8c68909a81f92b37febcac27bb19520e209316a7cec5bbd0' 
  AND token = 'AITm9ftp2N0OpyMgVhXzVDZj/vJTCrbMeT2bHP17EMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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