SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3612b7c336043ef8b25fbfa616174792ac0244647bf4eaf38f946aa24eb95a6' 
  AND token = '5bTyxaFlV3ONBFo4ESkvsIAcOCd7abxxbEXsIozFtxI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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