SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e00172677ca81477c129d0afb7d077c6756ff13944d134db4fdc5e64085965d3' 
  AND token = 'J8+zCfQk9d/WtH5E6+4oNvrBFhPfvQMEE/LuuamwDOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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