SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0742a2d445f4633f5c06766301436c51f52334009a822f28cfd1668cfafe76e2' 
  AND token = 'Y+dJxCzJCNs57HWI6L9DpHT5S8EIDHYbx1m0OewaWf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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