SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d4e400ea92dac64daf72407c4ba5d82adf9fbfc32effb545e8ba875bc761246' 
  AND token = 'qDo9g5902jLd7xnlA7Koewh6NwD8FPrOlzdlGGJeJtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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