SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c77ca2009520ad4d62f783c4e79e7ecc552b368261a52d7183c13c6e41353b9d' 
  AND token = 'lWhvxFC5vgTBIrSaExeZ/ohWdb4zUmdllUrQh52jwmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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