SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd46e6ef1fe1edd9bd71910980afe3a49030d3771f15718ea2468c55d9d594855' 
  AND token = 'gy95dk0iHCGs2DxjZ+YBorYZXdRWIVZHxac2qtzIDlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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