SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdeeed59938863e0d1ea178a09a3abacfe0a83a7c972250e49d626a876320c80' 
  AND token = '4yg/gvUKMyIS+DpspPAQwJMqp+yEkn86m+yRD1916Hg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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