SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62cef4beefa9a2251f5153e42bfc0c57fb606e958d13777fef690c0ba47221cc' 
  AND token = 'Ug0Zqm3mKL/6Tl1qzAW1daNt1zR9/FRpAPS5nFExQmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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