SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'afb898b3b95476688a4c460e7522f438b9fa952a8c80df8d9f1dc7d268e0216b' 
  AND token = 't+0T5cw7yVf/uQ1z1SvzTi8BWLMEnaq5bFBPbR5XbK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}