SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e329f896027eff831847bece8a57fa08d5aca1f20f729e928f495831f78f97e7' 
  AND token = '8znQBlqVZ/8YzsvyvtTG/mg6cDHnyAYF8CoL6v1ZBuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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