SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98f6e60e2961ac62fe46e0d02e299444addc1f296a5cfee60131488ce2f311b6' 
  AND token = 'IECod8vC6HE3QOGZVBuzqxhP4jOQrspKg3Ql/17ZnOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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