SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ead19c7db8f3e079cfe6d4eadf0dae16fe475212dfe1427ae0368d7cdc64bfdc' 
  AND token = '32zO3CofdziKmkqpwfmBndIaqvueDpTY9CKhhdVCj40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}