SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcf9035ac76db349d112b6408b403871633f3ba0afd22512229152431d5fc39b' 
  AND token = 'rCHJvLkUIQo+bPzel6KqHuMwlyDeBLPqra7vsXoqN9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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