SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc4c8335d2541f5a3b56a5061a5ad75394c7c17d1282e93528722b959bb6cbaf' 
  AND token = 'Tt3DEsG3/EuMlvtgE/v04MdI1gmYQp7Nm5Ci9SizRS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}