SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfd273a4ed955141ab038682e590d41dd75aa4cf25d1de278c437dfe6fedc8ef' 
  AND token = 'TOpa2nABz8zP5sPmJAcC789yxCMYR4g0n+B7ycQ1U68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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