SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '889c7d2e6bf5d95bd142793ca28757dd9d5cfeb46b1cb06118db4914218d9735' 
  AND token = 'j+aPKBuxSkfUcjC3MBCN1CvP3IHbIZlca/gNPwxniQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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