SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17b6eb80f606bb0431797c1e85642b69c8abba02cda28d1f85d1dcca6e27bd65' 
  AND token = 'DIB7hpeXkbhXGgZsL+hd+26DMrK1G3mT/IJOYmROzPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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