SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70e473206571baac8ec045d22cee4d47061374019f79ce8d5dbc8776ae4d7cd7' 
  AND token = 'C2fYD6ewiAvDrN21UsaFRjY7jpajtqhcGyZf4LEHBik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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