SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90bc06bcefb4f2c163a05bde7051f1b3bed4b5bdceb0758e74ea65e10d05074c' 
  AND token = 'vZOUEUX2COhu9dKCV53xb2AnQgmRnwaHO/+7QCnyxxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}