SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a9a688a14ddaede776c563c8f05204baafca37484ba886a7ecf6fcb06b37273' 
  AND token = 'QyIecNT2pX1sgrkkEpj0grCKnNBlsiApAmMI5aEg49Y=' 
  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"
    }
  }
}