SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebf09c62034bcf81a782fffc9af4709f2674b653a48578f9e6fd03f761637a3e' 
  AND token = 'ErW+ZkuT/nxQGU7sPHxj5QYIes0vj+pgYSs2ljZHxEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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