SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '734959b8e9f2998a26e8967a6d20eafb9e2f90d96256dd4fcab36840e8dcbea2' 
  AND token = 'Jtk3hhhsgbLN8wcdHwajdGqybSOsxgh3G7tDZCEwuEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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