SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8d9baac5ba922e7d3f17427d64a761b774e335cf53c900c1d5284bcb6f3614e' 
  AND token = 'gQ2cxRL3ZSscXi+JJKV19Kx3gz9i68ImaLAfh1P4Ojw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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