SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab66799f6c1d67a16f4dbd156bea51885473ebceab452217a18163a68009e417' 
  AND token = 'PfK/mNVOE2QXi8h7wVvhZjlGeBWlHaCc2S3m37OaoQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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