SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b11412d3607221c0022159c9c3bb5fdb824a1895d071f93dc1da37f87dd5da2e' 
  AND token = '7LqXth6ygLTC3+O7uAbeJXKMxTI9pF+mUFKvfWZo2K4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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