SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fa9f94a23c927c0efbc2196160f4d91bbcba7be9d59c0db30960b31d9a5eff9' 
  AND token = 'ztXShpKIB6auWT5ov/AuMe/rg7HavrHAqHPy7jIGqLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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