SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1847cacc1929e896ab948da26d6b6aeb0fae9e567a1e5fef73b9eba25e7e7ad2' 
  AND token = 'BHktuRJR1OK33vG4+zhOk4HiJ9vgJEBd6mYYLhZTi+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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