SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '58c86cb00619d35f67c71298ea6e161fbbaf3e73985550ce8874833cd1fe5a64' 
  AND token = 'LiV8YF+dH8HuBN6fQds3Kvm+JOiNLRxVHVGcB/Z+I2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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