SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47df020a0a7d18747b672e9fc7f9117aceec173fc2841f8d330f62fda14f915b' 
  AND token = 'Y36RgyklmXVn5n5V9WR0JOm9Ij6oGUvq/fJmhwr3+PM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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